Fluids in the work place and environment, particularly toxic vapors, may pose a significant hazard to personnel, and recent government health and safety regulations are focusing on such toxic liquids and vapors as a matter of concern. For example and typically, a large number of workers are being exposed routinely to toxic organic vapors, including halo hydrocarbons, benzene, vinyl chloride, acrylonitrile and toluene diisocyanate, which are often present in the work place and in the environment. Other gases which pose a health threat include industrial gases, such as phosgene, hydrogen cyanide, chlorine, formaldehyde and ammonia, and industrial contaminants, such as the oxides of sulfur, nitrogen and carbon, hydrogen sulfide and the like. There is no totally satisfactory method currently available to alert immediately an individual to overexposure to the hazards of toxic vapors, and, therefore, there is an urgent need to develop a toxic-vapor-monitoring, personnel badge for individual use which is convenient, rapid and specific in its response and is easy to interpret, is reliable and inexpensive.
In particular, a toxic-monitoring badge is desired which is subject to an immediate change as the concentration of toxic vapors varies, so that an individual, who may be desensitized by low-level toxic vapors in a nonhazardous concentration, may be alerted immediately by a rapid response when a high-level concentration of the vapor occurs, which would not be detected, for example, by subsequent instrumental analysis, such as in gaseous-contaminant dosimeters which contain means to inhibit convection movement of the diffused gases, such as those dosimeters described in U.S. Pat. Nos. 3,985,017 and 4,102,201.
Present, off-the-shelf, monitoring systems often are complex and bulky and require a back-up laboratory analysis to provide suitable results and often are expensive and time-consuming, requiring the use of fans, motors and power supplies. Other personnel dosimeters, such as the passive dosimeters, are unable to operate as a simple, clip-on badge, based on time-weighted averages, and do not function to warn a worker exposed to a toxic vapor at the real time of the hazard. Therefore, there exists a need for a simple, rapid, personnel, toxic badge element which can clearly display hazardous dose levels in a clearly visible manner and which is rapidly responsive to detect or monitor fluids on exposure or contact.